I kind of like Profit and Loss
. Yes, it's another romance-of-the-week, but it does help define Quark's character rather significantly. It shows that he's not, in fact, the universe's ultimate materialist. He is willing to look beyond profit in some situations, an aspect of him that later episodes really develop. And, the romance doesn't feel like it comes out of left field.
As for Garak, I could take or leave this appearance. Robinson does the best with what he's given and makes it slightly above average, but it's not up to his usual greatness.